国内外众创经济研究述评——基于文献计量与扎根理论分析

立足众创时代特征,运用文献计量对1999—2018年间1701篇国内外众创文献挖掘分析,探寻众创经济特点主题,探析众创发展知识基础,探求众创研究演进脉络,并获取众创经济视域下核心语句和高频词语,运用扎根理论对抽取的126篇的众创文献样本进行三级编码,进而构建众创研究的整合性理论框架,探究众创研究的系统性发展图景。研究表明,众创理论假说大量问世,众创文献热点主题包括六类,众创经济研究存在两种演进趋势,众创经济治理系统理论具有三个维度;未来应关注众创主体思辨性、众创要素系统性和众创技术本土化等专题研究。     

优化营商环境,推动发展高质量经济

促进中国经济高质量发展的必由之路是优化营商环境,提升区域竞争力。目前我国面临着国际内外的复杂局势,经济未来的发展趋势不容乐观,为此我们要深入落实新的发展理念,建立新的发展思路,构建新的发展格局。优化营商环境应实现建立服务型政府,实现企业经营环节的全覆盖,降低制度性交易成本、建立完善的商业系统生态链、打造具有中国特色的营商环境。     

基于激光点云的高墩垂直度偏差分析方法

现代桥梁工程中高墩桥梁屡见不鲜,桥墩垂直度已成为评定桥墩施工质量的重要指标之一.以新疆某特大桥项目为依托,针对高墩垂直度检测结果实用性低的问题,提出一种采用三维激光扫描技术对高墩垂直度进行非接触测量分析的方法.利用三维激光扫描仪快速获取高墩结构全局点云信息,对桥墩点云进行拼接、降噪等预处理,采用编程算法实现了桥墩节段中心点和垂直度偏差的计算,并得到了垂直度偏差变化规律图.最后将该方法与传统方法进行对比.结果表明:利用三维激光扫描技术对高墩进行快速测量,能够获取桥墩中心轴线的三维空间线型,精确分析并定位最大偏差位置,显著提高垂直度测量结果的实用性,具有良好的工程应用前景,并为后续研究桥墩垂直度问题提供了新思路.     

The rise of Mexican entrepreneurial migration to the United States: A mixed‐embeddedness approach

Although many studies have analyzed the behavior of high‐skilled migration to the United States, few have focused on the escalating migration of Mexican entrepreneurs, and particularly on the determinants of this kind of high‐skilled migration. This article addresses this gap through a qualitative approach conforming to quantitative procedures, based on 20 in‐depth interviews applied to Mexican entrepreneurs working and/or living in the United States. Theoretically, a mixed‐embeddedness approach guides this research because it allows examining both the individual characteristics of Mexican entrepreneurs, and the influence of the home and host countries' institutional contexts on their business endeavors. Findings revealed Mexico's institutional weaknesses, such as insecurity, corruption, and bureaucracy, are important drivers of migration but so are the perception of a friendly U.S. fiscal system, the search for a better quality of life, and the appeal of a more transparent business environment.     

乘积型指数滤波器及其在多目标时延估计中的应用

指数滤波器是一类新构造出来的输出信噪比和目标时延分辨力随指数变化的滤波器，该滤波器在损失一定输出信噪比的前提下可以有效提高目标时延分辨力，从而提高目标时延估计精度,但仅采用单个指数滤波器仍存在输出信噪比和目标时延分辨力均达不到实际需求的情况。在乘积型高阶模糊函数乘积运算的启发下，在指数滤波器的基础上提出了一种新的乘积型指数滤波器，并分析了该乘积型指数滤波器的输出信噪比及目标时延分辨力等性能。仿真实验表明，所提的乘积型指数滤波器在低信噪比情况下可以更有效提高多目标时延估计精度，且算法简单易于实现，适用于背景复杂的多目标参数估计任务。     

基于熵值法的高质量发展综合评价研究

探索高质量发展评价指标体系是当前社会各界面临的极富挑战性和开创性工作。从生产、分配、交换和消费四个环节选取23个指标构建高质量发展指标体系,利用熵值法对2000—2015年我国经济高质量发展进行评价。在此基础上从提升全要素生产率、调节国民收入分配格局、助力文化消费以及防范市场风险等层面提出政策建议。     

A Historical Review of Postponement Research

This historical review traces the development of postponement research starting in the fifties. The focus is on seven related themes: connecting form and time postponement, conceptual extensions to postponement, decoupling points, design for postponement, customization and mass customization, factors favoring postponement implementation, and postponement in global settings. Within these themes, the review includes concepts such as postponement costs, decoupling points, part commonality, and the impact of demand correlations on the benefits of postponement. The review suggests that substantial progress has been made in postponement research.     

地方技能型高水平大学视角下的校内实训室建设与管理--以六安职业技术学院旅游管理实训中心为例

以六安职业技术学院旅游管理实训中心为例，探讨在建设地方技能型高水平大学的过程中，如何来建设与管理校内实训室。     

Time,Arbitrage, and the Law of One Price: The Case for a Paradigm Shift

Consider a Competitive, Efficient, and Frictionless Economy (CEFE) where resources are scarce at any date, and hence money as a valid claim against scarce resources is also scarce. In this economy, there is always price competition, which can at any date generate an unlimited number of arbitrage opportunities. For example, at any date, opportunities can exist to buy and sell each one of the contracts for delivery of the same good or asset at multiple prices currently as well as on an infinite number of future dates. I prove all arbitrage transactions, including “spot” transactions, tie up arbitrageurs’ capital representing money, good or asset such that this capital cannot be used for any other purpose for a non-zero quantity of time. This makes it impossible to exploit all arbitrage opportunities with the scarce capital available at any date and leads to an infinite number of unexploited opportunities and a non-negligible opportunity cost of the capital tied-up in arbitrage transactions, represented by each arbitrageur’s best missed arbitrage opportunity, if no better opportunity exits, hence the breakdown of the law of one price in its standard sense. This helps construct a new paradigm of CEFE which resolves long-standing theoretical, empirical, and experimental puzzles.     

X频段高频谱纯度频率合成器设计

针对高灵敏度接收机对频率合成器的高技术指标要求，构建了一种融合了直接模拟、直接数字以及间接数字的频率合成技术方案，根据该方案，成功实现了频率合成器的工程研制。通过测试，频率合成器相位噪声达-112 dBc/Hz@5 kHz，杂散抑制优于-75 dBc，频率分辨率小于1 kHz，10 MHz跳频时间约为13 μs，满足了高灵敏度接收机对频率合成器的高技术指标要求，为高纯度频率合成器的实现提供了一条新途径。